A multi-band coaxial four-ridged speaker combined feed source and manufacturing method

Abstract

The present invention provides a multi-band coaxial four-ridged horn combined feed and a manufacturing method, which relate to the fields of satellite communication, remote sensing and telemetry, and radio astronomy. The feed includes a coaxial horn, the inner conductor of the coaxial horn is a plain wall horn, the plain wall horn is indented inward relative to the horn mouth of the outer conductor of the coaxial horn, the tail flange of the plain wall horn is connected to the tail short-circuit plate of the outer conductor of the coaxial horn, and the outer conductor of the coaxial horn and / or the plain wall horn are provided with 4 ridges, the angle between adjacent ridges is 90 degrees, and each ridge is provided with a probe perpendicular to the central axis of the plain wall horn, the probe passes through the outer conductor of the coaxial horn and the ridge, and is inserted into the outer wall of the plain wall horn, and the probe is externally connected to the SMA socket for feeding. The present invention has excellent electrical performance, compact structure, high design freedom, and a wide range of application scenarios, and can be used as a dual-frequency shared feed or a triple-frequency shared feed.

Description

Technical Field

[0001] The invention relates to the fields of satellite communication, remote sensing and telemetry, and radio astronomy, and in particular to a multi-band coaxial four-ridged horn combined feed source and a manufacturing method thereof. Background Art

[0002] Reflector antennas have simple structures and superior performance, and are widely used in satellite communications, remote sensing, telemetry, radio astronomy, and other fields. In recent years, reflector antennas have gradually developed in the direction of multi-band and broadband. As the core component of reflector antennas, the performance of multi-band and broadband feeds directly affects the performance of the entire reflector antenna.

[0003] As one of the typical multi-band feed types, the coaxial combined feed realizes multi-frequency sharing by nesting circular waveguides in coaxial waveguides, where low-frequency signals propagate in the outer coaxial waveguide channel and high-frequency signals propagate in the central circular waveguide channel. The coaxial combined feed has two outstanding advantages: first, the high and low frequency signals are fed, transmitted and radiated in two relatively independent channels, and the dual-frequency microwave network can be simplified into two single-frequency microwave networks, greatly reducing the design difficulty; second, the high-order modes in the high and low frequency bands are easier to control, and the radiation pattern beam width can be basically kept stable, thereby achieving a higher antenna aperture efficiency.

[0004] In multi-band feed applications, the ratio of the lowest operating frequency of the high-frequency signal to the highest operating frequency of the low-frequency signal is called the high-low frequency ratio. When the high-low frequency ratio is large, the coaxial combined feed can well balance the performance of the high and low frequency bands, and the overall performance of the feed is excellent; but when the high-low frequency ratio is small, the high-frequency channel has a greater impact on the low-frequency channel, resulting in poor impedance characteristics and limited bandwidth in the low-frequency channel. The researchers improved the impedance matching characteristics of the low-frequency channel by applying multiple groups of impedance matching rings to the low-frequency channel. At the same time, they loaded a medium in the high-frequency circular waveguide channel to reduce the caliber and reduce the impact on the low-frequency channel, extending the low-frequency bandwidth to 2 times the frequency. However, after exceeding 2 times the frequency, the transmission characteristics of the low-frequency channel will deteriorate rapidly. It is difficult to achieve a multi-band coaxial combined feed with a low-frequency bandwidth above 2 times the frequency with existing technical means. Summary of the invention

[0005] The present invention aims to avoid the problems arising from the above technical background and provide a multi-band coaxial four-ridged horn combined feed source and a manufacturing method thereof. The present invention has the characteristics of good matching and high efficiency in illuminating the reflective surface antenna.

[0006] The technical solution adopted by the present invention is:

[0007] A multi-band coaxial four-ridged horn combined feed source comprises a coaxial horn, wherein the coaxial horn comprises a coaxial horn outer conductor and a coaxial horn inner conductor which are nested together, wherein the central axis of the coaxial horn inner conductor is consistent with the central axis of the coaxial horn outer conductor; wherein the coaxial horn inner conductor is a plain-walled horn, which is indented inward relative to the horn mouth surface of the coaxial horn outer conductor, wherein the tail flange of the plain-walled horn is connected to the tail short-circuit plate of the coaxial horn outer conductor, wherein four ridges are arranged on the inner wall of the coaxial horn outer conductor, wherein the angle between adjacent ridges is 90 degrees, wherein the curve of the inner wall of the coaxial horn outer conductor is fitted with the root of the ridges, wherein each ridge is provided with a probe which is perpendicular to the central axis of the plain-walled horn, wherein the probe passes through the coaxial horn outer conductor and the ridges, and is inserted into the outer wall of the plain-walled horn, and the probe is externally connected to an SMA socket for feeding.

[0008] A multi-band coaxial four-ridged horn combined feed source comprises a coaxial horn, wherein the coaxial horn comprises a coaxial horn outer conductor and a coaxial horn inner conductor which are nested together, wherein the central axis of the coaxial horn inner conductor is consistent with the central axis of the coaxial horn outer conductor; wherein the coaxial horn inner conductor is a plain-walled horn, which is indented inward relative to the horn mouth of the coaxial horn outer conductor, wherein the tail flange of the plain-walled horn is connected to the tail short-circuit plate of the coaxial horn outer conductor, wherein four ridges are arranged on the outer wall of the plain-walled horn, wherein the angle between adjacent ridges is 90 degrees, wherein each ridge is provided with a probe which is perpendicular to the central axis of the plain-walled horn, wherein the probe passes through the coaxial horn outer conductor and is inserted into the ridge, and the probe is externally connected to an SMA socket for feeding.

[0009] A multi-band coaxial four-ridged horn combined feed source comprises a coaxial horn, wherein the coaxial horn comprises a coaxial horn outer conductor and a coaxial horn inner conductor which are nested together, wherein the central axis of the coaxial horn inner conductor is consistent with the central axis of the coaxial horn outer conductor; wherein the coaxial horn inner conductor is a plain-walled horn, which is indented inward relative to the horn mouth of the coaxial horn outer conductor, wherein the tail flange of the plain-walled horn is connected to the tail short-circuit plate of the coaxial horn outer conductor, and four outer conductor ridges are arranged on the inner wall of the coaxial horn outer conductor. The angle between adjacent outer conductor ridges is 90 degrees. The curve of the inner wall of the outer conductor of the coaxial speaker fits with the root of the outer conductor ridge. Four inner conductor ridges are arranged on the outer wall of the plain wall speaker. The outer conductor ridges correspond to the inner conductor ridges one by one. The inner conductor ridges are arranged opposite to the corresponding outer conductor ridges. A probe perpendicular to the central axis of the plain wall speaker is provided at each outer conductor ridge. The probe passes through the outer conductor and the outer conductor ridge of the coaxial speaker and is inserted into the inner conductor ridge. The probe is connected to the SMA socket for power feeding.

[0010] Furthermore, it also includes a choke slot, which is located at the feed source head and connected to the outer wall of the outer conductor of the coaxial horn.

[0011] Furthermore, the ridge curves of the outer conductor ridge piece and the inner conductor ridge piece are exponential function curves or spline function curves, and the curve of the inner wall of the outer conductor of the coaxial speaker is an exponential function curve or a spline function curve.

[0012] Furthermore, the light wall horn includes a transmission section and a radiation section, wherein the transmission section is a circular waveguide with a constant radius along the axial direction, the radius is 0.279 times the cut-off wavelength, and the inner wall curve of the radiation section is a spline function curve.

[0013] The present invention also provides a method for manufacturing the multi-band coaxial four-ridged horn combined feed source, comprising the following steps:

[0014] Step 1, optimizing the design of the light wall speaker;

[0015] Step 2, constructing a coaxial speaker outer conductor with a ridge piece, combining the coaxial speaker outer conductor with a plain-wall speaker to form a coaxial speaker, and optimizing the design of the coaxial speaker outer conductor;

[0016] Step 3, optimizing the relative position relationship between the light wall speaker and the outer conductor of the coaxial speaker;

[0017] Step 4, connect the tail flange of the plain speaker to the tail short-circuit plate of the outer conductor of the coaxial speaker, and insert the probe.

[0018] Furthermore, the specific method of step 1 is:

[0019] The efficiency factor method is used to evaluate the performance of the light-wall horn. The optimization target is the antenna aperture efficiency, the constraint is the reflection coefficient, and the optimization variables are the structural parameters of the light-wall horn, including the coordinates of the discrete points on the inner wall curve of the light-wall horn.

[0020] Furthermore, in step 2, the specific method of optimizing the design of the outer conductor of the coaxial speaker is:

[0021] The efficiency factor method is used to evaluate the performance of the coaxial horn. The optimization target is the antenna aperture efficiency, the constraint is the reflection coefficient, and the optimization variables are the structural parameters of the outer conductor of the coaxial horn, including the coordinates of the discrete points of the coaxial outer conductor curve, the number of choke slots, the width and depth of each slot, and the coordinates of the discrete points of the ridge curve.

[0022] Furthermore, in step 3, the optimization target is the mutual influence between the high and low frequency bands, the constraint condition is the phase center consistency, and the optimization variable is the relative position relationship between the light wall speaker and the outer conductor of the coaxial speaker.

[0023] Compared with the background technology, the present invention has the following advantages:

[0024] 1. The present invention can expand the low-frequency bandwidth and improve the high-frequency performance. The present invention uses a coaxial four-ridged speaker nested light-walled speaker structure to achieve a multi-band coaxial combined feed source with a low-frequency bandwidth of 2.5 times. The low-frequency broadband characteristics of the present invention are mainly achieved by loading the ridge structure on the inner and outer conductors of the coaxial speaker. The ridge loading can reduce the first high-order mode TE of the coaxial waveguide. 11 The cut-off frequency of the mode can be increased, thereby expanding the low-frequency working bandwidth. After the coaxial speaker is added with ridges, its bandwidth characteristics are mainly determined by the ridge spacing, and the restrictions on the size of the coaxial inner conductor will be greatly reduced. Therefore, the coaxial high-frequency speaker can have a larger design space and freedom, and the performance of the high-frequency speaker can be further improved.

[0025] 2. The present invention can reduce the mutual influence between high and low frequency bands. The present invention reduces the mutual influence between high and low frequency bands by retracting the light wall horn inward by a certain distance relative to the coaxial horn mouth surface, making the phase centers of the high and low frequency bands consistent, and realizing high-efficiency irradiation of the feed source to the reflector antenna when working in multiple frequency bands.

[0026] 3. The structure of the present invention is compact and has a high degree of design freedom. The feed source adopts a coaxial nested structure to achieve multi-frequency sharing, and the ridges are loaded on the inner and outer conductors of the coaxial horn to further reduce the caliber. The structure is very compact and convenient for miniaturization design. The inner wall curve of the outer conductor of the coaxial horn, the ridge curve of the ridge, and the inner wall curve of the plain horn can adopt an exponential function curve or a spline function curve, which has a high degree of design freedom.

[0027] 4. The present invention has a wide range of application scenarios. The feed source can be used as a conventional dual-frequency shared feed source, with low-frequency signals transmitted and radiated in the coaxial waveguide channel and high-frequency signals transmitted and radiated in the central circular waveguide channel; since the low-frequency working bandwidth is very wide, reaching 2.5 times the frequency, it can cover two independent frequency bands, and combined with the light wall speaker to transmit and radiate high-frequency signals, it can be used as a three-frequency shared feed source. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of a multi-band coaxial four-ridge combined feed source with a coaxial speaker outer conductor and ridges.

[0029] Figure 2 It is a schematic diagram of a multi-band coaxial four-ridge combined feed source with ridges added to the outer wall of a plain-wall speaker (inner conductor of a coaxial speaker).

[0030] Figure 3 It is a schematic diagram of a multi-band coaxial four-ridged combined feed source in which both the outer conductor of the coaxial speaker and the outer wall of the plain-wall speaker (the inner conductor of the coaxial speaker) are ridged.

[0031] Explanation of the reference numerals: outer conductor of the coaxial horn 1, outer conductor ridge piece 21, inner conductor ridge piece 22, choke slot 3, probe 4, short-circuit plate 5, plain-wall horn 6, flange 7. DETAILED DESCRIPTION

[0032] The present invention is further described in detail below in conjunction with the accompanying drawings.

[0033] A multi-band coaxial four-ridged horn combined feed source comprises a coaxial horn, wherein the coaxial horn comprises a coaxial horn outer conductor and a coaxial horn inner conductor which are nested together, wherein the central axis of the coaxial horn inner conductor is consistent with the central axis of the coaxial horn outer conductor, wherein the coaxial horn inner conductor is a plain-walled horn, wherein the plain-walled horn is indented inwardly relative to the horn mouth surface of the coaxial horn outer conductor, wherein the tail flange of the plain-walled horn is connected to the tail short-circuit plate of the coaxial horn outer conductor, wherein four ridges are arranged on the coaxial horn outer conductor and / or the plain-walled horn, wherein the angle between adjacent ridges is 90 degrees, wherein each ridge is provided with a probe which is perpendicular to the central axis of the plain-walled horn, and the probe is externally connected to an SMA socket for feeding.

[0034] The feed is manufactured as follows:

[0035] Step 1, optimizing the design of the light wall speaker;

[0036] Step 2, constructing a coaxial speaker outer conductor, combining the coaxial speaker outer conductor with the light wall speaker to form a coaxial speaker, and optimizing the design of the coaxial speaker outer conductor and the ridge piece;

[0037] Step 3, optimizing the relative position relationship between the light wall speaker and the outer conductor of the coaxial speaker;

[0038] Step 4, connect the tail flange of the plain speaker to the tail short-circuit plate of the outer conductor of the coaxial speaker, and insert the probe.

[0039] The ridge piece in the feed source can be arranged on the inner wall of the outer conductor of the coaxial horn, can also be arranged on the outer wall of the plain-wall horn, or can be arranged on both the outer conductor of the coaxial horn and the plain-wall horn.

[0040] Figure 1 The figure shows a multi-band coaxial four-ridge combined feed source with a coaxial horn outer conductor and a ridge, including a coaxial horn outer conductor 1, an outer conductor ridge piece 21, a choke slot 3, a coaxial probe 4, a short-circuit plate 5, a plain-wall horn 6, and a flange 7.

[0041] The outer wall curve of the coaxial horn outer conductor 1 is a conical curve, which does not affect the feed performance and can be selected as any curve type. The inner wall curve of the coaxial horn outer conductor 1 is divided into two sections. The first section is a straight line, and the radius remains unchanged along the axial direction. The second section can be an exponential function curve or a spline function curve. The figure shows a spline function curve, and its shape is interpolated by multiple discrete points distributed along the axial direction.

[0042] The ridge piece 21 is connected to the inner wall of the coaxial speaker outer conductor 1, and the ridge piece 21 and the coaxial speaker outer conductor 1 are integrally formed. The ridge curve of the ridge piece 21 is divided into two sections, the first section is a straight line, corresponding to the first straight line section of the inner wall curve of the coaxial speaker outer conductor 1, and the radius along the axial direction remains unchanged, which can ensure the uniform transmission of the electromagnetic wave excited by the probe 4, and the second section can be an exponential function curve or a spline function curve, and the figure shows a spline function curve, and its shape is interpolated by multiple discrete points distributed along the axial direction.

[0043] The choke slot 3 is connected to the outer wall of the coaxial horn outer conductor 1 and is located at the head of the feed source. The number of choke slots 3 can be selected according to the performance of the feed source, and is generally 2 to 5. The choke slot can improve the rotational symmetry of the low-frequency radiation pattern of the feed source and improve the aperture efficiency.

[0044] The probe 4 is inserted into the light-walled horn 6 through the outer conductor 1 of the coaxial horn and the ridge 21. It is necessary to make holes in the outer conductor 1 of the coaxial horn, the ridge 21 and the outer wall of the light-walled horn 6. The ratio of the radius of the hole on the outer conductor 1 of the coaxial horn and the ridge 21 to the radius of the probe 4 is 2.301. The radius of the hole on the outer wall of the light-walled horn 6 is equal to that of the probe 4. The tolerance should be set reasonably to ensure that the probe 4 and the outer wall of the light-walled horn 6 are well matched. The probe 4 is fed by an external SMA socket. Equal-amplitude anti-phase feeding of a pair of probes symmetrically placed along the central axis can excite the TE of the coaxial waveguide. 11 mold.

[0045] The short-circuit plate 5 is located at the tail of the coaxial speaker outer conductor 1, and the distance from the probe 4 is 0.25 times of the working wavelength, which can improve the transmission characteristics in the low frequency band.

[0046] The light-wall horn 6 is nested in the outer conductor 1 of the coaxial horn, and is consistent with the central axis of the outer conductor 1 of the coaxial horn, and is indented a distance relative to the mouth of the outer conductor 1 of the coaxial horn, thereby reducing the mutual influence between the high and low frequency bands, making the high and low frequency bands consistent in center, and improving the efficiency of irradiating the reflective surface antenna. The tail flange 7 of the light-wall horn 6 is connected to the tail short-circuit plate 5 of the outer conductor 1 of the coaxial horn. The light-wall horn 6 is divided into a transmission section and a radiation section, wherein the transmission section is a circular waveguide with a constant radius along the axial direction, and the radius is 0.279 times the cut-off wavelength. The radiation section is located at the head of the light-wall horn, and the inner wall curve is a spline function curve, and its shape is interpolated by multiple discrete points distributed along the axial direction.

[0047] The inner circular waveguide channel of the light wall speaker 6 transmits and radiates high-frequency band signals, and the coaxial waveguide channel between the coaxial speaker outer conductor 1 and the light wall speaker 6 transmits and radiates low-frequency band signals.

[0048] By adjusting the inner wall curve of the coaxial speaker outer conductor 1 and the ridge curve shape of the ridge sheet 21, excellent transmission and radiation characteristics of low-frequency signals can be achieved. By adjusting the inner wall curve shape of the radiation section of the light-wall speaker 6, excellent transmission and radiation characteristics of high-frequency signals can be achieved.

[0049] The following takes a C / X / Ka triple-frequency common feed as an example to verify its transmission and radiation performance, as follows:

[0050] C-band operating frequency: 3.4-4.2GHz, 5.85-6.65GHz

[0051] X-band operating frequency: 7.25-7.75GHz, 7.9-8.4GHz

[0052] Ka-band operating frequency: 19.6-21.2GHz, 29.4-31.0GHz

[0053] The C / X band signal is transmitted and radiated in the coaxial waveguide channel between the outer conductor of the coaxial horn and the light wall horn. The C / X band working bandwidth is 2.5 times the frequency. The Ka band signal is transmitted and radiated in the circular waveguide channel inside the light wall horn. The half-irradiation angle of the feed source is 52°. The commercial software CST is used for simulation, which includes the following steps:

[0054] Step 1: Optimize the design of the light-wall speaker and use the efficiency factor method to evaluate the performance of the light-wall speaker. The optimization target is the antenna aperture efficiency, the constraint condition is the reflection coefficient, and the optimization variable is the structural parameters of the light-wall speaker, specifically the coordinates of the discrete points of the inner wall curve of the light-wall speaker. The coordinates of the discrete points of the inner wall curve of the light-wall speaker after optimization are shown in Table 1 (unit: mm).

[0055]

[0056] Step 2: Construct the outer conductor of the coaxial horn with ridges, combine the outer conductor of the coaxial horn with the plain wall horn to form a coaxial horn, optimize the design of the outer conductor of the coaxial horn, and use the efficiency factor method to evaluate the performance of the coaxial horn. The optimization target is the antenna aperture efficiency, the constraint condition is the reflection coefficient, and the optimization variables are the structural parameters of the outer conductor of the coaxial horn, specifically the coordinates of the discrete points of the inner wall curve of the outer conductor of the coaxial horn, the number of choke slots, the width and depth of each slot, and the coordinates of the discrete points of the ridge curve. The coordinates of the discrete points of the inner wall curve of the outer conductor of the coaxial horn after optimization are shown in Table 2, the coordinates of the discrete points of the ridge curve are shown in Table 3, the number of choke slots is 2, and the specific parameters are shown in Table 4 (unit is mm).

[0057]

[0058]

[0059]

[0060] Step 3: Optimize the relative position relationship between the light-wall speaker and the outer conductor of the coaxial speaker. The optimization target is the mutual influence between the high and low frequency bands. The constraint condition is the consistency of the phase center. The optimization variable is the relative position relationship between the light-wall speaker and the outer conductor of the coaxial speaker. After optimization, the light-wall speaker is indented 7.18mm relative to the outer conductor of the coaxial speaker.

[0061] Step 4, connect the tail flange of the plain-wall horn to the tail short-circuit plate of the outer conductor of the coaxial horn, and insert the probe to assemble a multi-band coaxial four-ridge horn combined feed source.

[0062] The C / X / Ka three-band common feed designed by the above method has good transmission and radiation characteristics. The reflection coefficient of the C / X band is lower than -10.24dB, and the edge illumination level is between -5.54dB and -11.76dB. The reflection coefficient of the Ka band is lower than -25.86dB, and the edge illumination level is between -7.20dB and -14.42dB. The aperture efficiency of the C / X / Ka three-band antenna is higher than 55% for the standard forward feed reflector antenna with an illumination focal ratio of 0.51.

[0063] Figure 2 The multi-band coaxial four-ridged horn combination feed source is shown with a ridge added to the outer wall of a plain-walled horn (inner conductor of a coaxial horn), including a coaxial horn outer conductor 1, an inner conductor ridge piece 22, a choke slot 3, a coaxial probe 4, a short-circuit plate 5, a plain-walled horn 6, and a flange 7.

[0064] The outer wall curve of the coaxial horn outer conductor 1 is a conical curve, which does not affect the feed performance and can be selected as any curve type. The inner wall curve of the coaxial horn outer conductor 1 is divided into two sections. The first section is a straight line, and the radius remains unchanged along the axial direction. The second section can be an exponential function curve or a spline function curve. The figure shows a spline function curve, and its shape is interpolated by multiple discrete points distributed along the axial direction.

[0065] The ridge piece 22 is connected to the outer wall of the light-wall speaker 6, and the ridge piece 22 and the light-wall speaker 6 are integrally formed. The ridge curve of the ridge piece 22 is divided into two sections, the first section is a straight line, corresponding to the first straight line section of the inner wall curve of the coaxial speaker outer conductor 1, and the radius remains unchanged along the axial direction, which can ensure the uniform transmission of the electromagnetic wave excited by the probe 4, and the second section can be an exponential function curve or a spline function curve, and the figure shows a spline function curve, and its shape is interpolated by multiple discrete points distributed along the axial direction.

[0066] The choke slot 3 is connected to the outer wall of the coaxial horn outer conductor 1 and is located at the head of the feed source. The number of choke slots 3 can be selected according to the performance of the feed source, and is generally 2 to 5. The choke slot can improve the rotational symmetry of the low-frequency radiation pattern of the feed source and improve the aperture efficiency.

[0067] The probe 4 passes through the outer conductor 1 of the coaxial horn and is inserted into the ridge 22. It is necessary to make holes in the outer conductor 1 of the coaxial horn and the ridge 22. The ratio of the radius of the hole on the outer conductor 1 of the coaxial horn to the radius of the probe 4 is 2.301. The radius of the hole on the ridge 22 is equal to that of the probe 4. The tolerance should be set reasonably to ensure that the probe 4 and the ridge 22 cooperate well. The probe 4 is fed by an external SMA socket. Equal-amplitude anti-phase feeding of a pair of probes symmetrically placed along the central axis can excite the TE of the coaxial waveguide. 11 mold.

[0068] The short-circuit plate 5 is located at the tail of the coaxial speaker outer conductor 1, and the distance from the probe 4 is 0.25 times of the working wavelength, which can improve the transmission characteristics in the low frequency band.

[0069] The light-wall horn 6 is nested in the outer conductor 1 of the coaxial horn, and is consistent with the central axis of the outer conductor 1 of the coaxial horn, and is indented a distance relative to the mouth of the outer conductor 1 of the coaxial horn, thereby reducing the mutual influence between the high and low frequency bands, making the high and low frequency bands consistent in center, and improving the efficiency of irradiating the reflective surface antenna. The tail flange 7 of the light-wall horn 6 is connected to the tail short-circuit plate 5 of the outer conductor 1 of the coaxial horn. The light-wall horn 6 is divided into a transmission section and a radiation section, wherein the transmission section is a circular waveguide with a constant radius along the axial direction, and the radius is 0.279 times the cut-off wavelength. The radiation section is located at the head of the light-wall horn, and the inner wall curve is a spline function curve, and its shape is interpolated by multiple discrete points distributed along the axial direction.

[0070] The inner circular waveguide channel of the light wall speaker 6 transmits and radiates high-frequency band signals, and the coaxial waveguide channel between the coaxial speaker outer conductor 1 and the light wall speaker 6 transmits and radiates low-frequency band signals.

[0071] By adjusting the inner wall curve of the coaxial speaker outer conductor 1 and the ridge curve shape of the ridge sheet 22, excellent transmission and radiation characteristics of low-frequency signals can be achieved. By adjusting the inner wall curve shape of the radiation section of the light-wall speaker 6, excellent transmission and radiation characteristics of high-frequency signals can be achieved.

[0072] The following takes a C / X / Ka triple-frequency common feed as an example to verify its transmission and radiation performance, as follows:

[0073] C-band operating frequency: 3.4-4.2GHz, 5.85-6.65GHz

[0074] X-band operating frequency: 7.25-7.75GHz, 7.9-8.4GHz

[0075] Ka-band operating frequency: 19.6-21.2GHz, 29.4-31.0GHz

[0076] The C / X band signal is transmitted and radiated in the coaxial waveguide channel between the outer conductor of the coaxial horn and the light wall horn. The C / X band working bandwidth is 2.5 times the frequency. The Ka band signal is transmitted and radiated in the circular waveguide channel inside the light wall horn. The half-irradiation angle of the feed source is 52°. The commercial software CST is used for simulation, which includes the following steps:

[0077] Step 1: Optimize the design of the light-wall horn and use the efficiency factor method to evaluate the performance of the light-wall horn. The optimization target is the antenna aperture efficiency, the constraint condition is the reflection coefficient, and the optimization variable is the structural parameters of the light-wall horn, specifically the coordinates of the discrete points on the inner wall curve of the light-wall horn.

[0078] Step 2: Construct the outer conductor of the coaxial horn, combine the outer conductor of the coaxial horn with the plain-wall horn to form a coaxial horn, optimize the design of the outer conductor of the coaxial horn and the ridge on the outer wall of the plain-wall horn, and use the efficiency factor method to evaluate the performance of the coaxial horn. The optimization target is the antenna aperture efficiency, the constraint condition is the reflection coefficient, and the optimization variables are the structural parameters of the outer conductor and the ridge of the coaxial horn, specifically the coordinates of the discrete points of the inner wall curve of the outer conductor of the coaxial horn, the number of choke slots, the width and depth of each slot, and the coordinates of the discrete points of the ridge curve of the ridge of the outer wall of the plain-wall horn.

[0079] Step 3: Optimize the relative position relationship between the light-wall speaker and the outer conductor of the coaxial speaker. The optimization target is the mutual influence between the high and low frequency bands. The constraint condition is the consistency of the phase center. The optimization variable is the relative position relationship between the light-wall speaker and the outer conductor of the coaxial speaker.

[0080] Step 4, connect the tail flange of the plain-wall horn to the tail short-circuit plate of the outer conductor of the coaxial horn, and insert the probe to assemble a multi-band coaxial four-ridge horn combined feed source.

[0081] The C / X / Ka triple-frequency shared feed designed by the above method has good transmission characteristics and radiation characteristics, good impedance matching characteristics, good rotational symmetry of the radiation pattern within the illumination angle, low cross-polarization level, and can achieve high-efficiency illumination for the reflector antenna.

[0082] Figure 3 The figure shows a multi-band coaxial four-ridged horn combination feed source in which both the outer conductor of the coaxial horn and the outer wall of the plain-wall horn (the inner conductor of the coaxial horn) are ridged, comprising a coaxial horn outer conductor 1, an outer conductor ridge piece 21, an inner conductor ridge piece 22, a choke slot 3, a coaxial probe 4, a short-circuit plate 5, a plain-wall horn 6, and a flange 7.

[0083] The outer wall curve of the coaxial horn outer conductor 1 is a conical curve, which does not affect the feed performance and can be selected as any curve type. The inner wall curve of the coaxial horn outer conductor 1 is divided into two sections. The first section is a straight line, and the radius remains unchanged along the axial direction. The second section can be an exponential function curve or a spline function curve. The figure shows a spline function curve, and its shape is interpolated by multiple discrete points distributed along the axial direction.

[0084] The ridge piece 21 is connected to the inner wall of the coaxial speaker outer conductor 1, and the ridge piece 21 and the coaxial speaker outer conductor 1 are integrally formed. The ridge curve of the ridge piece 21 is divided into two sections, the first section is a straight line, corresponding to the first straight line section of the inner wall curve of the coaxial speaker outer conductor 1, and the radius along the axial direction remains unchanged, which can ensure the uniform transmission of the electromagnetic wave excited by the probe 4, and the second section can be an exponential function curve or a spline function curve, and the figure shows a spline function curve, and its shape is interpolated by multiple discrete points distributed along the axial direction.

[0085] The ridge piece 22 is connected to the outer wall of the light-wall speaker 6, and the ridge piece 22 and the light-wall speaker 6 are integrally formed. The ridge curve of the ridge piece 22 is divided into two sections, the first section is a straight line, corresponding to the first straight line section of the inner wall curve of the coaxial speaker outer conductor 1 and the first straight line section of the ridge piece 21 curve, and the radius along the axial direction remains unchanged, which can ensure the uniform transmission of the electromagnetic wave excited by the probe 4, and the second section can be an exponential function curve or a spline function curve, and the figure shows a spline function curve, and its shape is interpolated by multiple discrete points distributed along the axial direction.

[0086] The choke slot 3 is connected to the outer wall of the coaxial horn outer conductor 1 and is located at the head of the feed source. The number of choke slots 3 can be selected according to the performance of the feed source, and is generally 2 to 5. The choke slot can improve the rotational symmetry of the low-frequency radiation pattern of the feed source and improve the aperture efficiency.

[0087] Probe 4 passes through the outer conductor 1 of the coaxial horn and the ridge 21 and is inserted into the ridge 22. It is necessary to make holes in the outer conductor 1 of the coaxial horn, the ridge 21 and the ridge 22. The ratio of the radius of the holes on the outer conductor 1 of the coaxial horn and the ridge 21 to the radius of probe 4 is 2.301. The radius of the hole on the ridge 22 is equal to that of probe 4. The tolerance should be set reasonably to ensure that probe 4 and ridge 22 cooperate well. Probe 4 is fed by an external SMA socket. Equal-amplitude anti-phase feeding of a pair of probes symmetrically placed along the central axis can excite the TE of the coaxial waveguide. 11 mold.

[0088] The short-circuit plate 5 is located at the tail of the coaxial speaker outer conductor 1, and the distance from the probe 4 is 0.25 times of the working wavelength, which can improve the transmission characteristics in the low frequency band.

[0089] The light-wall horn 6 is nested in the outer conductor 1 of the coaxial horn, and is consistent with the central axis of the outer conductor 1 of the coaxial horn, and is indented a distance relative to the mouth of the outer conductor 1 of the coaxial horn, thereby reducing the mutual influence between the high and low frequency bands, making the high and low frequency bands consistent in center, and improving the efficiency of irradiating the reflective surface antenna. The tail flange 7 of the light-wall horn 6 is connected to the tail short-circuit plate 5 of the outer conductor 1 of the coaxial horn. The light-wall horn 6 is divided into a transmission section and a radiation section, wherein the transmission section is a circular waveguide with a constant radius along the axial direction, and the radius is 0.279 times the cut-off wavelength. The radiation section is located at the head of the light-wall horn, and the inner wall curve is a spline function curve, and its shape is interpolated by multiple discrete points distributed along the axial direction.

[0090] The inner circular waveguide channel of the light wall speaker 6 transmits and radiates high-frequency band signals, and the coaxial waveguide channel between the coaxial speaker outer conductor 1 and the light wall speaker 6 transmits and radiates low-frequency band signals.

[0091] By adjusting the inner wall curve of the coaxial speaker outer conductor 1, the ridge 21 and the ridge curve shape of the ridge 22, excellent transmission and radiation characteristics of low-frequency signals can be achieved. By adjusting the inner wall curve shape of the radiation section of the light-wall speaker 6, excellent transmission and radiation characteristics of high-frequency signals can be achieved.

[0092] The following takes a C / X / Ka triple-frequency common feed as an example to verify its transmission and radiation performance, as follows:

[0093] C-band operating frequency: 3.4-4.2GHz, 5.85-6.65GHz

[0094] X-band operating frequency: 7.25-7.75GHz, 7.9-8.4GHz

[0095] Ka-band operating frequency: 19.6-21.2GHz, 29.4-31.0GHz

[0096] The C / X band signal is transmitted and radiated in the coaxial waveguide channel between the outer conductor of the coaxial horn and the light wall horn. The C / X band working bandwidth is 2.5 times the frequency. The Ka band signal is transmitted and radiated in the circular waveguide channel inside the light wall horn. The half-irradiation angle of the feed source is 52°. The commercial software CST is used for simulation, which includes the following steps:

[0097] Step 1: Optimize the design of the light-wall horn and use the efficiency factor method to evaluate the performance of the light-wall horn. The optimization target is the antenna aperture efficiency, the constraint condition is the reflection coefficient, and the optimization variable is the structural parameters of the light-wall horn, specifically the coordinates of the discrete points on the inner wall curve of the light-wall horn.

[0098] Step 2: Construct an outer conductor of the coaxial horn with ridges, combine the outer conductor of the coaxial horn with the plain-wall horn to form a coaxial horn, optimize the design of the outer conductor of the coaxial horn and the inner and outer ridges, and use the efficiency factor method to evaluate the performance of the coaxial horn. The optimization target is the antenna aperture efficiency, the constraint condition is the reflection coefficient, and the optimization variables are the structural parameters of the outer conductor of the coaxial horn and the outer wall ridges of the plain-wall horn, specifically the coordinates of the discrete points of the inner wall curve of the outer conductor of the coaxial horn, the number of choke slots, the width and depth of each slot, the coordinates of the discrete points of the ridge curve of the outer conductor ridge, and the coordinates of the discrete points of the ridge curve of the outer wall ridge of the plain-wall horn.

[0099] Step 3: Optimize the relative position relationship between the light-wall speaker and the outer conductor of the coaxial speaker. The optimization target is the mutual influence between the high and low frequency bands. The constraint condition is the consistency of the phase center. The optimization variable is the relative position relationship between the light-wall speaker and the outer conductor of the coaxial speaker.

[0100] Step 4, connect the tail flange of the plain-wall horn to the tail short-circuit plate of the outer conductor of the coaxial horn, and insert the probe to assemble a multi-band coaxial four-ridge horn combined feed source.

[0101] The C / X / Ka triple-frequency shared feed designed by the above method has good transmission characteristics and radiation characteristics, good impedance matching characteristics, good rotational symmetry of the radiation pattern within the illumination angle, low cross-polarization level, and can achieve high-efficiency illumination for the reflector antenna.

[0102] From the above results, it can be seen that compared with the prior art, the present invention realizes low-frequency wide-band characteristics by loading ridges on the outer conductor of the coaxial speaker or the plain-wall speaker, and reduces the mutual influence between the high and low frequency bands by retracting the plain-wall speaker inward for a certain distance relative to the coaxial speaker mouth, thereby finally realizing a working bandwidth of 2.5 times the low frequency band, and having good transmission and radiation characteristics in multiple frequency bands and excellent electrical performance.

[0103] The present invention has excellent electrical performance, compact structure, high design freedom, and wide application scenarios, and can be used as a dual-frequency shared feed source or a triple-frequency shared feed source.

Claims

1. A multi-band coaxial four-ridged horn combined feed source, comprising a coaxial horn, wherein the coaxial horn comprises a coaxial horn outer conductor and a coaxial horn inner conductor nested together, wherein the central axis of the coaxial horn inner conductor is consistent with the central axis of the coaxial horn outer conductor; characterized in that: The inner conductor of the coaxial horn is a plain-wall horn, which is indented inward relative to the horn mouth of the outer conductor of the coaxial horn. The tail flange of the plain-wall horn is connected to the tail short-circuit plate of the outer conductor of the coaxial horn. Four ridges are provided on the inner wall of the outer conductor of the coaxial horn, and the angle between adjacent ridges is 90 degrees. The curve of the inner wall of the outer conductor of the coaxial horn fits the root of the ridge. A probe perpendicular to the central axis of the plain-wall horn is provided at each ridge. The probe passes through the outer conductor of the coaxial horn and the ridge, and is inserted into the outer wall of the plain-wall horn. The probe is externally connected to an SMA socket for feeding.

2. A multi-band coaxial four-ridged horn combined feed source, comprising a coaxial horn, wherein the coaxial horn comprises a coaxial horn outer conductor and a coaxial horn inner conductor nested together, wherein the central axis of the coaxial horn inner conductor is consistent with the central axis of the coaxial horn outer conductor; characterized in that: The inner conductor of the coaxial horn is a plain-wall horn, which is indented inward relative to the horn mouth of the outer conductor of the coaxial horn. The tail flange of the plain-wall horn is connected to the tail short-circuit plate of the outer conductor of the coaxial horn. Four ridges are arranged on the outer wall of the plain-wall horn, and the angle between adjacent ridges is 90 degrees. A probe perpendicular to the central axis of the plain-wall horn is arranged at each ridge. The probe passes through the outer conductor of the coaxial horn and is inserted into the ridge. The probe is externally connected to an SMA socket for power feeding.

3. A multi-band coaxial four-ridged horn combined feed source, comprising a coaxial horn, wherein the coaxial horn comprises a coaxial horn outer conductor and a coaxial horn inner conductor nested together, wherein the central axis of the coaxial horn inner conductor is consistent with the central axis of the coaxial horn outer conductor; characterized in that: The inner conductor of the coaxial horn is a plain-wall horn, which is indented inward relative to the horn mouth of the outer conductor of the coaxial horn. The tail flange of the plain-wall horn is connected to the tail short-circuit plate of the outer conductor of the coaxial horn. Four outer conductor ridges are arranged on the inner wall of the outer conductor of the coaxial horn. The angle between adjacent outer conductor ridges is 90 degrees. The curve of the inner wall of the outer conductor of the coaxial horn fits the root of the outer conductor ridge. Four inner conductor ridges are arranged on the outer wall of the plain-wall horn. The outer conductor ridges correspond to the inner conductor ridges one by one. The inner conductor ridges are arranged opposite to the corresponding outer conductor ridges. A probe perpendicular to the central axis of the plain-wall horn is provided at each outer conductor ridge. The probe passes through the outer conductor of the coaxial horn and the outer conductor ridge, and is inserted into the inner conductor ridge. The probe is externally connected to an SMA socket for feeding.

4. A multi-band coaxial four-ridged horn combined feed source according to claim 3, characterized in that: It also includes a choke slot, which is located at the feed source head and connected to the outer wall of the outer conductor of the coaxial horn.

5. The multi-band coaxial quad-ridged horn combined feed source according to claim 3, characterized in that: The ridge curves of the outer conductor ridge piece and the inner conductor ridge piece are exponential function curves or spline function curves, and the curve of the inner wall of the outer conductor of the coaxial speaker is an exponential function curve or a spline function curve.

6. The multi-band coaxial four-ridged horn combined feed source according to claim 3, characterized in that: The light wall horn comprises a transmission section and a radiation section, wherein the transmission section is a circular waveguide with a constant radius along the axial direction, the radius being 0.279 times the cut-off wavelength, and the inner wall curve of the radiation section is a spline function curve.

7. A manufacturing method, characterized in that: The method for manufacturing the multi-band coaxial four-ridged horn combined feed source as claimed in claim 1 comprises the following steps: Step 1, optimizing the design of the light wall speaker; Step 2, constructing a coaxial speaker outer conductor with a ridge piece, combining the coaxial speaker outer conductor with a plain speaker to form a coaxial speaker, and optimizing the design of the coaxial speaker outer conductor; Step 3, optimizing the relative position relationship between the light wall speaker and the outer conductor of the coaxial speaker; Step 4, connect the tail flange of the plain speaker to the tail short-circuit plate of the outer conductor of the coaxial speaker, and insert the probe.

8. The manufacturing method according to claim 7, characterized in that: The specific method of step 1 is: The efficiency factor method is used to evaluate the performance of the light-wall horn. The optimization target is the antenna aperture efficiency, the constraint is the reflection coefficient, and the optimization variables are the structural parameters of the light-wall horn, including the coordinates of the discrete points on the inner wall curve of the light-wall horn.

9. The manufacturing method according to claim 7, characterized in that: In step 2, the specific method of optimizing the design of the outer conductor of the coaxial speaker is: The efficiency factor method is used to evaluate the performance of the coaxial horn. The optimization target is the antenna aperture efficiency, the constraint is the reflection coefficient, and the optimization variables are the structural parameters of the outer conductor of the coaxial horn, including the coordinates of the discrete points of the coaxial outer conductor curve, the number of choke slots, the width and depth of each slot, and the coordinates of the discrete points of the ridge curve.

10. The manufacturing method according to claim 7, characterized in that: In step 3, the optimization target is the mutual influence between the high and low frequency bands, the constraint condition is the phase center consistency, and the optimization variable is the relative position relationship between the light wall speaker and the outer conductor of the coaxial speaker.

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